Not Applicable.
1. Field of the Invention
This invention relates to slide-out drive mechanisms of the type that are used in recreational vehicles for enlarging the space inside the vehicle when the vehicle is parked.
2. Discussion of the Prior Art
Slide-out drive systems for recreational vehicles, e.g., trailers and motor homes, for sliding out a room to enlarge the space of the vehicle when it is parked, are known from patents such as U.S. Pat. No. 5,833,296 (xe2x80x9cthe ""296 patentxe2x80x9d), the disclosure of which is hereby incorporated by reference. Referring to FIG. 1, in such a system, one or more (two as illustrated) telescoping rails 12 have their outer ends 14 attached to the room section to be slid out and are driven by a drive means, which may include an electric motor 16 and/or hand cranks 18, at one or more locations which are accessible to the user. By turning the shaft 20 in one direction or the other, the rails 12 are either extended or retracted. As disclosed in the ""296 patent, when an electric motor 16 is provided, it is preferred to have the motor include a brake to keep the rails 12 retracted when the room is retracted, and extended when it is extended.
However, particularly if the dive system is strictly a manually driven system, or if it is driven with an electric motor which does not have a brake, other means must be provided to keep the rails 12 retracted in a fixed position. In the past, such means have included travel bars, which typically may be a bar that makes physical contact with the slide-out room and a fixed part of the recreational vehicle to keep the slide-out room retracted during travel. It is an object of the present invention to provide a means to keep the room retracted, or extended, as an alternative to the use of slide-out travel bars or similar means.
SUMMARY OF THE INVENTION
A slide-out drive system of the present invention may be the same as that disclosed in the ""296 patent except that in the present invention there is a gear lock on the shaft which is used to drive the rails in and out. As disclosed in the ""296 patent, this shaft drives gears which mesh with racks which are fixed to the slide-out rails. The shaft is driven by an electric motor, typically through a gear box, or by a hand crank through a gear box. According to the present invention, a radially fixed gear can be moved axially into and out of engagement with one of the gears that is in driving engagement with the shaft so as to lock the rotation of the shaft or not
The fixed gear may be advantageously provided in a manual drive gearbox. That way, whether an electric motor is provided to drive the system or not, the braking function of the fixed gear will still be available. If a motor is not provided, the manual gearbox is the primary means to drive the slide-out, whereas if a motor is provided, the manual gearbox functions as a backup in case of power or motor failure.
In addition, the fixed gear is preferably moved axially into or out of engagement with the gear that is in driving engagement with the drive shaft of the rails by a hand operated cam mechanisms The hand operated cam mechanism gives good tactile feedback and assurance to the user that the system is locked in place and also provides a simple means of applying or releasing the lock.
The foregoing and other objects and advantages of the invention will appear in the detailed description which follows. In the description, reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention.